📌 Topic 02 of 6 · Chapter 03 · Nuclear Technology
India’s 3-Stage Nuclear Programme
Uranium → Plutonium → Thorium — Homi Bhabha’s vision — complete notes for UPSC & PSC exams.
⚛️ India’s 3-Stage Nuclear Programme
Conceived by Dr. Homi J. Bhabha to exploit India’s vast thorium reserves and achieve energy independence:
| Stage | Reactor Type | Fuel | Byproduct | Status |
|---|---|---|---|---|
| Stage 1 | PHWR (Pressurised Heavy Water Reactor) | Natural Uranium (U-238 + U-235) | Plutonium-239 | Operational — 22 reactors at 7 plants |
| Stage 2 | FBR (Fast Breeder Reactor) | Plutonium-239 (from Stage 1) | Uranium-233 (from Thorium-232) | PFBR under construction at Kalpakkam |
| Stage 3 | AHWR (Advanced Heavy Water Reactor) | Uranium-233 + Thorium-232 | More U-233 | Under development |
⚛️ Why Thorium?
- India has the world’s largest thorium reserves (~25% of world total)
- Thorium reserves: mainly in Kerala and Tamil Nadu (monazite sands)
- Thorium (Th-232) cannot be used directly as nuclear fuel — it is fertile (not fissile)
- In a breeder reactor, Th-232 absorbs a neutron → becomes U-233 (fissile) → can be used as fuel
- Thorium is more abundant than uranium; produces less long-lived radioactive waste
- Stage 3 will make India energy independent using thorium
⚛️ PFBR — Prototype Fast Breeder Reactor
- India’s first Fast Breeder Reactor (FBR) — part of Stage 2
- Location: Kalpakkam, Tamil Nadu
- Capacity: 500 MW
- Fuel: Plutonium-uranium mixed oxide (MOX)
- Coolant: Liquid sodium (no moderator — fast neutrons)
- Operated by: BHAVINI (Bharatiya Nabhikiya Vidyut Nigam Limited)
- Will breed more fuel (U-233 from Th-232) than it consumes
⭐ Key Facts — 3-Stage Programme:
• Stage 1 = PHWR = natural uranium = produces plutonium
• Stage 2 = FBR = plutonium = breeds U-233 from thorium
• Stage 3 = AHWR = U-233 + thorium = exploits India’s thorium reserves
• India = world’s largest thorium reserves (~25%) = Kerala, Tamil Nadu
• PFBR = Kalpakkam = 500 MW = liquid sodium coolant = BHAVINI
• Stage 1 = PHWR = natural uranium = produces plutonium
• Stage 2 = FBR = plutonium = breeds U-233 from thorium
• Stage 3 = AHWR = U-233 + thorium = exploits India’s thorium reserves
• India = world’s largest thorium reserves (~25%) = Kerala, Tamil Nadu
• PFBR = Kalpakkam = 500 MW = liquid sodium coolant = BHAVINI